Bicycle frame



FIG. 1 is a front elevational view of a bicycle frame showing my new design, the rear elevational view being a mirror image thereof;

FIG. 2 is a side view, taken from the left side of FIG. 1;

FIG. 3 is a side view, taken from the right side of FIG. 1;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof.

The broken lines showing a crankset, fork, stem, bars, seatpost, saddle, wheels and pedals in FIG. 1 are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a bicycle frame, as shown and described. 